This study examines the online writing and revision behaviors of university language learners. In small groups, 53 intermediate German students from three classes at three different universities created wiki pages with background information about a novel read in class. All meaning- and language-related revisions were analyzed to determine whether students revised only their own contributions (cooperation) or took responsibility for the text as a whole (collaboration). Results indicate that students utilized both collaborative and cooperative strategies to make formal revisions, but they worked more cooperatively when making content changes. Group members did not take on any specific task roles with regards to formal revisions, but they were engaged in the project to varying degrees. While most students contributed to content and editing of their wiki page as required, some students did not do their share of the work and engaged in social loafing and free riding. The study demonstrates wikis' great potential for collaborative and autonomous work, but it also underlines the need for clear tasks and some teacher intervention. Suggestions to mitigate social loafing and free riding in group work are discussed.